Isocladosporin, a Biologically Active Isomer of Cladosporin from Cladosporium cladosporioides

1993 ◽  
Vol 56 (8) ◽  
pp. 1397-1401 ◽  
Author(s):  
John M. Jacyno ◽  
John S. Harwood ◽  
Horace G. Cutler ◽  
Mee-Kyoung Lee
Keyword(s):  
Cladosporium Cladosporioides ◽  
Biologically Active ◽  
Active Isomer

Synthesis of a biologically active isomer of frontalin and some new products from acylative decarboxylation of 3-methyltricarballylic acid

1990 ◽  
Vol 68 (5) ◽  
pp. 782-786 ◽  
Author(s):  
George M. Strunz ◽  
Chao-Mei Yu ◽  
Li Ya ◽  
Peter S. White ◽  
E. A. Dixon
Keyword(s):  
Acetic Anhydride ◽  
Functional Groups ◽  
Bark Beetles ◽  
New Products ◽  
Major Product ◽  
Biologically Active ◽  
Catalysed Reaction ◽  
Active Isomer ◽  
Pheromone Analogue ◽  
Simple Manipulation

2-Acetonyl-2-methylsuccinic anhydride, 3, the major product from base-catalysed reaction of 3-methyltricarballylic acid with acetic anhydride, was converted by simple manipulation of functional groups into 1,5-dimethyl-2,7-dioxabicyclo[3.2.1]octane. This bicyclic ketal (6) is isomeric with frontalin, 7, an aggregation pheromone for Dendroctonus bark beetles. It elicited electroantennogram responses in D. ponderosae and D. rufipennis. Besides 3 and the known compounds, 4 and 5, two new minor products, 8 and 9, were identified from base-catalysed acylative decarboxylation of 3-methyltricarballylic acid. Keywords: pheromone analogue, Dendroctonus, bark beetles.

Synthesis of a biologically active isomer of kotalanol, a naturally occurring glucosidase inhibitor

2010 ◽  
Vol 18 (8) ◽  
pp. 2829-2835 ◽  
Author(s):  
Razieh Eskandari ◽  
Kumarasamy Jayakanthan ◽  
Douglas A. Kuntz ◽  
David R. Rose ◽  
B. Mario Pinto
Keyword(s):  
Biologically Active ◽  
Glucosidase Inhibitor ◽  
Naturally Occurring ◽  
Active Isomer

ChemInform Abstract: Synthesis of Isobrassilexin, a Biologically Active Isomer of Brassilexin, a Cruciferae Phytoalexin.

ChemInform ◽  
2010 ◽  
Vol 25 (37) ◽  
pp. no-no
Author(s):  
M. BARBIER ◽  
M. DEVYS ◽  
C. TEMPETE ◽  
A. KOLLMANN ◽  
J.-F. BOUSQUET
Keyword(s):  
Biologically Active ◽  
Active Isomer

The Absorption of the Diastereoisomers of 5-Methyltetrahydropteroylglutamate in Man: A Carrier-Mediated Process

1973 ◽  
Vol 45 (5) ◽  
pp. 625-631 ◽  
Author(s):  
D. G. Weir ◽  
J. P. Brown ◽  
D. S. Freedman ◽  
J. M. Scott
Keyword(s):  
Urinary Excretion ◽  
Coeliac Disease ◽  
Intestinal Absorption ◽  
Intravenous Injection ◽  
Biologically Active ◽  
Human Intestinal Absorption ◽  
Naturally Occurring ◽  
Active Isomer

1. The two diastereoisomers of 5-methyltetrahydropteroylglutamate, the form of folate that predominates in food and bile, were prepared chemically. 2. Their intestinal absorption was compared by means of the urinary-excretion method of 3H-labelled compounds and it was found that the naturally occurring biologically active isomer was excreted to a greater extent. Studies of the clearance of the two forms after intravenous injection showed that this difference was due to preferential intestinal absorption of the naturally occurring isomer. 3. In four patients with coeliac disease, the absorption of the naturally occurring isomer was depressed to the same range as the inactive isomer. 4. Since the two diastereoisomers are chemically inseparable, these results indicate that a carrier-mediated process is involved in the human intestinal absorption of this form of reduced folate.

Phase I and pharmacologic studies of intraperitoneal leucovorin and 5-fluorouracil in patients with advanced cancer.

1986 ◽  
Vol 4 (10) ◽  
pp. 1510-1517 ◽  
Author(s):  
S G Arbuck ◽  
F Trave ◽  
H O Douglass ◽  
H Nava ◽  
S Zakrzewski ◽  
...  
Keyword(s):  
Advanced Cancer ◽  
Performance Status ◽  
Single Agent ◽  
Eastern Cooperative Oncology Group ◽  
Malignant Ascites ◽  
Biologically Active ◽  
Ecog Performance Status ◽  
Time Curve ◽  
Once Daily ◽  
Active Isomer

Many patients with gastrointestinal (GI) tumors develop extensive peritoneal and serosal metastasis and/or malignant ascites which respond poorly to available treatments. Twelve patients with tumors confined primarily to the intraabdominal cavity were treated with intraperitoneal (IP) 5-fluorouracil (5-FU) in escalating concentrations (2 to 4 mmol/L) in combination with leucovorin (dl-5-formyltetrahydrofolic acid or folinic acid; dl-CF) in a 2-L volume, either by eight consecutive four-hour dwells or once daily for five days. CF dose was 20.8 or 104 mumol/L. Nine of the patients had pancreatic carcinoma, one had stomach carcinoma, and two had hepatobiliary neoplasms. Median age was 62.5 years and median Eastern Cooperative Oncology Group (ECOG) performance status was 3. Toxicity included mucositis, diarrhea, nausea and vomiting, leucopenia, skin rash, and abdominal pain, and was similar to that previously reported for IP 5-FU used as a single agent. Four episodes of peritonitis occurred, but all patients responded to antibiotics. At the 20.8 mumol/L dose, dl-CF concentration in the peritoneal fluid declined from 10.4 +/- 3.0 3.0 mumol/L at one hour to 4.9 +/- 2.2 mumol/L at four hours, corresponding to a mean absorption half-life of 127 +/- 49 minutes and a mean peritoneal clearance of 13.0 +/- 4.5 mL/min. Decline was biphasic in all but five of the 19 exchanges evaluated. The levels of l-CF (biologically active isomer of dl-CF) were 2.8 +/- 2.5 mumol/L after 60 minutes and 1.2 +/- 0.7 mumol/L after four hours. The peritoneal area under the concentration v time curve (AUC) for 5-FU increased proportionally with dose. For example, the AUC at 2.0 and 3.5 mmol/L was 129 +/- 25 and 201 +/- 23 mmol/L X minute, respectively. However, the maximal peritoneal to plasma AUC ratio was 461 at the 2 mmol/L dose, but decreased with increasing doses as systemic clearance decreased. This regimen was well tolerated in patients with advanced cancer, but must be evaluated further to determine its clinical efficacy.

Synthesis of Isobrassilexin, a Biologically Active Isomer of Brassilexin, a Cruciferac Phytoalexin

1993 ◽  
Vol 23 (22) ◽  
pp. 3109-3117 ◽  
Author(s):  
Michel Barbier ◽  
Michel Devys ◽  
Christiane Tempěte ◽  
Albert Kollmann ◽  
Jean-Francois Bousquet
Keyword(s):  
Biologically Active ◽  
Active Isomer

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

Depletion and Reconstitution of Active E. Coli Ribosomes

1975 ◽  
Vol 33 ◽  
pp. 640-641
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Protein Biosynthesis ◽  
Large Subunit ◽  
High Resolution Electron Microscopy ◽  
Small Subunit ◽  
Structure And Function ◽  
Biologically Active ◽  
Biological Macromolecules ◽  
E Coli ◽  
Resolution Electron ◽  
And Function

Correlations between structure and function of biological macromolecules have been studied intensively for many years, mostly by indirect methods. High resolution electron microscopy is a unique tool which can provide such information directly by comparing the conformation of biopolymers in their biologically active and inactive state. We have correlated the structure and function of ribosomes, ribonucleoprotein particles which are the site of protein biosynthesis. 70S E. coli ribosomes, used in this experiment, are composed of two subunits - large (50S) and small (30S). The large subunit consists of 34 proteins and two different ribonucleic acid molecules. The small subunit contains 21 proteins and one RNA molecule. All proteins (with the exception of L7 and L12) are present in one copy per ribosome.This study deals with the changes in the fine structure of E. coli ribosomes depleted of proteins L7 and L12. These proteins are unique in many aspects.

Fractionation of the Biologically Active Large Molecular Components of Human Gastric Content

1959 ◽  
Vol 37 (4) ◽  
pp. 439-444 ◽  
Author(s):  
Ranwel Caputto ◽  
William O. Smith ◽  
Jordan Tang ◽  
Raul E. Trucco ◽  
Walter Joel ◽  
...  
Keyword(s):  
Gastric Content ◽  
Biologically Active ◽  
Molecular Components
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